Enameled range boiler



NOV- 24 1942-- H. R. cANFu-:LD ,2,303,197

E NAMELED RANGE BOILER Nov. 24, 1942. H. R. CANFIELD 2,303,197

ENAMELED RANGE BOILER Filed Oct. 23, 1939 3 Sheefcs-Sheet 2 NOV. 24, 1942. H, R, CANFlELD 2,303,197

ENAMELED RANGE BOILER Filed Oct. 23', 1939 3 Sheets-Sheet 3 j? INVENTOR.

yrigidity at the juncture.

Patented Nov. 24, 1942 UNITED STATES PATENT ol-"EICE` l 2,303,191 l I ENAMELED RANGE colma Harry R. Canfield, Cleveland, h10, assigner, by

mesne assignments, to Porcelain Steels, Cleveland, Ohio, a corporation of Ohio Inc., C

Application october z3, 193s, serial No. 300,330

' s claims. (ci. isz-17) This invention relates to containers of the range boiler type: and in some aspects relates to range boilers having a heating tube or flue therein. 'I'he invention relates particularly to range boilers the walls of which are coated with vitreous enamel.

vIt has heretofore been proposed to coat the inner, or inner and outer, walls of a range boiler with vitreous enamel. It is also generally recognized that the most economical way to fabricate a range boiler from metal is to construct it from preformed sheet metal parts secured together. In view of the extensivedevelopment of enameled sheet metal ware generally, it would, at first consideration, appear a simple and obvious matter to coat a. range boiler, made from pieces of sheet metal, with enamel. As a matter of fact, unexpected problems arise for which there is not an obvious solution.

The joints between the several pieces of the boiler must join the pieces so integrally and rigidly at their junctures, that there can be no hinging or other relative movement of one piece upon another, when the boiler is subjected to internal pressure in use, otherwise the enamel coat will crack, and expose thev metal to the corrosive action of the hot water contained in the boiler.

Welding at the junctures of the pieces, if carried out by a process which joins them integrally throughout the juncture, provides the necessary It has been proposed to flash weld the end heads on the body of the range boiler to take advantage of the superiority of the flash type of weld for enameling purposes, but since this makes of the boiler a container closed against inspection of its interior, it presents the problem of obtaining a uniform distribution of the wet enamel slip over the inside as well as over the outside surface; and, furthermore, it renders it dimcult if not impossible to insure that the formation or fusing of the enamel on the inside walls of the boiler, will be in the presence of sufficient oxygen to insure adhesion of the enamel to the sheet metal, or to prevent the enamel slip from sweating and forming irregularly while being dried preparatory to fusing.

'I'he present invention has been made with a View to overcoming the above mentioned and other dimculties in the making of an enameled range boiler.

It is among the objects of the invention:

To provide generally an improved construction of range boiler;

To provide a range boiler constructed from .small number of pieces secured together in an improved manner.

'Other objects will be apparent -to those skilled in the art to which my invention appertalns.

My invention is fully disclosed in the following description in connection with the accompanying drawings in which,

Fig. 1 is a view partly in longitudinal section of a preferred form of range boiler embodying my invention and having a longitudinal internal heat transmitting tube or flue extending therethrough;

- Fig. 2 is a cross-sectional view to an enlarged scale illustrating the upper head of the boiler of Fig. 1 in the process of making it;

Figs. 3 and 4 are views illustrating an operation performed on the head of Fig. 2 to reduce the peripheral portion thereof to exact circularity and reduced thickness preparatory to flash welding it on the boiler body;

Fig. 5 is a.` view similar to Fig. 2, illustrating the lower head of Fig. 1 and an operation performed thereon to reduce the periphery of a central re-entrant portion to exact circularity and reduced thickness for ilash welding a heating ilue of Fig. `1 thereto;

Figs. 6 and 7 are separate views of. two mainv view taken trating one means of attaching a supporting leg to the boiler of Fig. 1 and shown in elevation in Fis. 1:

Figs. 13 and 14 are views, to a smaller scale and simpliiled, of the boiler of Fig. 1, illustrating modifications.

A completely developed embodiment of my invention is illustrated in Fig. 1 and various` features of its construction, the method of making it, and some of the machinery for performing the method, will now be described in connection with a description of the fabricating method.

The boiler may conveniently be considered as assembled from two units. a body unit A and a head unit B, shown separately in Figs. 6 and 7 respectively.

The body unit A comprises a body I, Figs. 1 and 7, formed from sheet metal, preferably steel, by rolling or bending the Sheet metal into hollow cylindrical form, and then flash welding a longitudinal seam thereon to vform an integral tube. The flash weld may be performed by well known flash welding machines, such for example, as those used to flash weld the bodies of barrels, and the flash fins internally and externally, may be tooled off by the well known machines employed in such processes.

The lower open end of the tube thus made has a flange 9 formed thereon by press forming, rolling or spinning, extending radially outwardly and a circular series of perforations I0, see Figs. 'I and 9. is made therein.

It is contemplated that the upper end of the body I, will be flash-welded to the upper head II of the boiler by a flash welding operation.

c and it is therefore desirable that both the end of the body and head, at the welded juncture, be of the same diameter and thickness.

To this end, the head Il is preferably constructed as follows, referring more particularly to Figs. 2, 3 and 4. By a pressing and forming operation the head I I, generally circular in cross section, is formed as in Fig. 2 having an upwardly projecting central collar I2 thereon. The head is generally of downwardly open cup form and at its lower periphery is formed with an out;

wardly extending peripheral flange I3. The main body of the head, as shown at I4, is of relatively greater thickness than the wall of the body I. This is for the reason that internal pressure in the boiler in use will tend to bulge the head II outwardly and if it it were thus to yield it would crack the enamel coat when formed thereon. Immediately above the lateral flange I3, the skirt of the head, as shown at I5, is press formed and drawn to reduced thickness, and to approximately the thickness of the wall of the body I. The ange I3 is formed on the head during the process of making it to facilitate the drawing of the skirt I5 to substantially circular form and to the said reduced thickness.

It is believed that sheet metal forming and drawing operations such as those described for the head I I are suiliciently well known not to require illustration or description herein.

The flange I3 is now removed by the steps of method illustrated somewhat diagrammatically in Figs. 3 and 4. The skirt I5 is telescoped over the lower annular element I6 ofa cutter, the outer annular element of which is shown at I'I. The skirt I3 rests upon a shoulder of the element I6. The element I1 is then telescoped downwardly over the skirt and moved downwardly in the directionof the arrow I9, Fig. 4, to the position in Fig. 4, shearing oi the flange I3. The lower portion of the skirt I5 is forced into a corner I9 formed on the shoulder I8 and the outer cutter element I1, while shearing off the flange I3, trues up the skirt I5 to a true cylinder and of predetermined diameter corresponding to that of the upper end of the body I.

The annular edge of the head skirt I5 is now welded upon the upper end of the body I by the well known flash welding process and inasmuch as the two parts being welded are of the same diameter and thickness as described above, they will be completely and integrally joined. The

welded juncture is indicated at 22, Figs. 1 and 7.

As to the unit B, and referring to Figs; 1 and 6, an internal flue tube 25 and a lower head 24 are made, and these two parts are Joined by a flash weld juncture indicated at 26. The flue tube 25 is formed from sheet metal, and may be formed by rolling a sheet into tubular formand flash welding it along a longitudinal seam, indicated at 21, Fig. 6.

The upper end of the flue 25 is rolled or press formed to provide a radially inwardly extending flange 28 for a purpose to be described, and this may be accomplished by bending the wall of the flue outwardly as at 29 and then inwardly to form the flange. The flange 28 is provided with a circular series of perforations 30-33 corresponding to a series of perforations 23 in the upper head.

The head 24 is shown in Fig. 5 to an enlarged scale. It is generally of cup form and the central part is formed with a stub tube 3i terminating in an inwardly extending flange 32, the flange being provided to facilitate the drawing of the end of the stub tube into a skirt 33.

The flange 32 is then cut off by inner and outer cutters 34 and 35 operating similarly to the cutters described in connection with Figs. 3 and 4, which leaves the skirt 33 of true circular form and of a predetermined diameter, corresponding with the diameter and thickness of the lower end of the flue tube 25.

The end of the skirt 33 and the lower end of the flue tube 25 are then flashwelded together, the juncture being indicated at 26, Figs. 1 and 6.

The head 24 is formed with an outwardly extending flange 38 provided with a circular series of perforations 39, corresponding to the perforations Ill-I0 in the body flange 9.

'I'he upper head 9 is formed with upwardly outwardly projecting tubular bosses 40-40, Figs. 1, 2 and '7, for the joining thereto of a conduitreceiving spud to be described; and the lower head 24 has a similar laterally extending tubular boss 4I, formed therein, Figs. 1, 6 and 5: and the side wall of the body I has like bosses 4242, formed therein, Figs. 1 and 7. Spuds are Welded to these outwardly open bosses and may, if desired, all be alike, by which conduits may be detachably connected to the boiler to communicate with its interior. One form of such spud connection is shown in Fig. 1 at 64-65.

Referring again to Figs. 2 and '7, the upper head adjacent to the collar I2, as at 52, is formed to be substantially planar and at right angles to the axis, and the said perforations 23 are in this planar portion.

Referring to Figs. 6 and 7, I have indicated a grinding operation which may be performed upon the upper end of the unit A. The flange 28 of the flue tube may be ground off along the line 53 in a plane at right angles to the axis of the flue, and gauged a predetermined distance C from the upper side of the flange 38 of the lower head 24. A similar grinding operation may be performed on the plane 54 at the lower end of the body I, gauging from the planar portion 52 of the upper head the same distance C as for the unit B, of Fig. 6.

The two units A and B of Figs. '7 and 6 are now ready to be enameled. They may be cleaned, pickled, etc., by well known methods. and a coating of wet enamel slip applied upon the entire inner, and preferably also outer, surfaces of the' body I and head II; and likewise upon the flue '26 and the head 24, and the same is then dried by well known means.

It will be observed that the Vflue 25 is Wide open at both ends so that air may circulate upwardly therethrough to aid in drying the slip without sweating, and that similarly, the unit A, being wide open at the bottom and having an opening upwardly through the collar I2, may have air circulated therethrough for the same purpose.

The two units are now fired to form the vitreous enamel, and, again, air may circulate freely through the interior of, as well as over the entire surface of the parts to amply supply oxygen which, as is well known, is necessary to insure adherence of the enamel coat to the steel.

During the application of the slip and after the enamel is fired and cooled, the interior of the unit A may be carefully inspected to insure a continuous uniform coat, being, as it is, wide open at the bottom. The unit B may similarly be inspected. e v

The enamel coat thusformed is shown on the outside of the body and the upper head, Fig. 1, at 51, and on the inside of the body and upper head at 68, and is shown on the inside of the flue and on the outside of the lower head at 59, and on the outside of the flue and on the inside of the head at 68.

The two enameled boiler units A and B, above described are now bolted together, as shown in Fig. 1, and as shown to a larger scale in Figs. 8 to 10. The holes 38-38 in flue ange 28 of unit B are aligned with the holes 23 of the upper boiler head II of unit A, and bolts 61 are projected therethrough; and the perforations 39 in the lower head 24 of the unit B are aligned withA the perforations I8 in the flange 9 of unit A and bolts 65 are projected therethrough,

In order to provide a pressure and liquid tight juncture and to avoid injury to the enamel coat, a packing ring'18 is laid upon the head II and an outer rigid metal ring 1I is laid on the packing; a packing ring 69 is laid under the head I|' and between the head and the flue flange 28. A packing ring 12 is placed under the flange 28 and a rigid ring 13 is laid on the packing 12. The bolts 61 are projected through all of the parts thus described through aligned perforations therein. The ring 1| may be a continuous ring since it may be telescoped into place over the collar I2. The ring 13, to assemble it, must be inserted downwardly through the collar I2 and being of larger diameter than the hole throgh the collar is made in pieces, preferably two, as shown in Fig. at 13A-13A, which can be inserted through the collar I2. The clamping nuts on the bolts 61 are shownl on the inside of the flue but can, if preferred, be on the outside of the ring 1|,

In Fig. 11 is shown a modification of the multipart ring. the. pieces being indicated at '13B-43B, this ring differing from that of Fig.

10 in that the two parts abut each other diag-V onally as shown at 14, whereas the parts of the `ring, Fig. 10, abut upon radial portions as at 15.

In Fig. 9, the juncture at the lower end of the boiler is illustrated and is generally similar to that of Fig. 8. The upper ring 16 is preferably in pieces, like the ring 13 in order that it may be of smaller diameter than would be necessary if it were to be telescoped downwardly from the upper end of the boiler over the spuds at 42-42. The ring can thusbe asesmbled into the joint by moving its parts laterally into position, em-

bracing the boiler, 'Ihe lower ring 11 may be a solid ring.

It is to be observed, as shown in Figs. 8 and 9, that theyinner edge of the flange 28, the upper end of the collar I2, and the outer edges of the flanges 8 and 38, are round to eliminate square corners, and I have found that if this provision is made the enamel will flowand form continuously and unbrokenly thereover which greatly improves the appearance of the boiler at these points, and its entire surface is rendered rust proof. Similarly the flanges are formed with large diameter curves at 18, on the collar I2, 88 at the upper end of the flue 25, 8| at thedlange 9, and 82 at the flange 88, to insure a continuous coat of enamel.

In Fig. 12 is illustrated one means for attach- .ing a support, such as a leg or legs 88 to the boiler. The flange juncture including the flanges 9 and 38 is utilized for this purpose, the flanges being located near the lower end of the boiler and being external thereto. The lower ring '11 has a plurality of studs 84 projecting downwardly therefrom and preferably secured thereto by welding and disposed between adjacent pairs of bolts 68. 'Ihe legs 83 may be press formed from sheet metal and have upper flanges 85 perforated to receive the bolts 84; and nuts 86 onvthe bolts rigidly secure the legs to the ring 11.

In the modification shown in Fig. 13, the method of procedure to make the boiler is simi lar to that for making the boiler of Fig. 1, but the construction diifers. in that Ithe flue 81 is flash welded at 98 to the body 9|, making a,

unitary structure of the flue and the body and lower head. The upper end of the ilue is bolted, as shown at 92, to the underside of the upper head 93 and the upper head and the upper end of the body 9| are provided with flanges 94 and` bolted together. The legs 96 may be welded to the lower head 89 and the enamel coat formed over the legs concurrently with that on the out-l side of the boiler. 'I'he form of Fig. 13 is another two-piece structure bolted together as in the form of Fig, 1. Y

In Fig. 14 is shown a three-piece boiler. The

' flue 41 is flash welded to the lower head 98 at 99.

The body |88 and lower head 98 have flanges |8I and |82 bolted together. The upper end of the body and the upper head |83 have anges 94 and 95 bolted together. The upper end of the flue 91 is bolted to the upper head as at |83. The legs |86 are again bolted to the lower flange |82 or to the lower ring |81.

Referring again to the form of Fig. 1, it will be observed that the drawing, Figs. 1 `and 6, the peripheral portion or skirt of the lower head 24 and the adjacent ange 38 are illustrated as of reduced thickness, thinner than the main portion of the head and approximately 'the same thickness as the body I. While this may, in

some cases, be desirable it is not essential. All.

parts of the' lower head 24 maybe of the same thickness. v

In connection with assembling the twoA units A and Bof Fig. 1 (and for a like reason as to the forms of Figs. 13 and 14) it will be advantageous to use packing rings above the flue flange 28 and above the head flange 38, of equal thickness to take advantage of the gauged overall dimension C referred to in connection with Figs. 6 and 7. In some cases it may not be necessary to grind the units as described for Figs. 6 and 7.

The outwardly extending flanges at the juncture of the boiler parts, for example, the flanges 9 and 38, Fig. 1,` and the rings 18 thereabove, may be used to support heat insulation indicated in broken lines at IIB, Fig. 1.

Any well'known type of heater may be used to heat water in the boilers described above having central flues, such as the flue 25 of Fig. 1. A burner may be disposed to apply heat on the lower head 24, the hot gases of combustion passing up through the flue and the heat thereof being transmitted through the wall of the flue into the water surrounding it. Or a burner may be located in the flue at the lower portion thereof. Any desired enclosure for the heater may be provided at the lower end of the boiler.

A stack or pipe to carry away gaseous products of combustion may be fitted over the collar I2 on the upper head, as shown at H1, Fig. l.

While I have referred to flash-welding as the preferred type of welding to be utilized in joining parts integrally together, it will be understood that in some cases other types of welding may be employed; and in any case, after a weld has been made, any suitable means or method may be employed to remove roughness, ns, etc., at the Weld to condition it to take a solid coat of enamel thereon.

From a reading of the foregoing description, in connection with the accompanying drawings, it will become apparent to those skilled in the art that my invention is not limited to the exact details of construction illustrated and described, nor to the exact steps of method employed. Changes and modifications may be made within the spirit of my invention and without sacrificing its advantages, and all such changes and modifications are intended to be comprehended within my invention, as come within the scope of the appended claims.

I claim:

1. In a range boiler, a body unit and a head unit; the body unit comprising a tubular sheet metal body and a cup form sheet metal head of greater thickness than the body and having a peripheral skirt of substantially the same thickness as the body ash welded to one end of the body, the other end of the body being open and having an outwardly laterally extending Iperipheral flange; the head unit comprising a head formed from relatively thick sheet metal and having a laterally extending peripheral flange, and at the interior portion of the head having an inwardly extending inner skirt the terminal of which is of reduced thickness; and a sheet metal flue tube of substantially the same thickness as the reduced portion of the inner skirt and flash welded at one end thereto; the free end of the flue tube being formed with an inwardly r-adially extending flange; the peripheral flanges of the body unit and head unit being bolted together and the flange at the free end of the flue tube being bolted to the inner surface of the ash welded head; the flash welded head being provided with a perforation aligned with the flue tube.

2. The range boiler described in claim 1 and in which the perforation in the flash welded head is provided with an outwardly extending peripheral collar aligned with the flue tube for telescoping with an exterior pipe.

3. In a range boiler a vertically disposable tubular body; a head at each end of the body; the upper head having a generally central opening therein; the lower head' having a generally central opening therein sealedly continuing at its periphery with one end oi' a flue tube; at least one of the heads being Joined to the body by means of outwardly extending connected flanges on the body and said head, and the upper end .of the flue tube being provided with a radially inwardly extending annular tube flange disposed inwardly of and substantially aligned with the opening of the upper head; and the tube flange being bolted to the underside of the upper head by bolts projected through aligned perforations provided in the upper head and in the tube flange and accessible through the upper head opening.

4. A range boiler composed of two sheet metal units; one unit comprising a tubular boiler body having a peripheral flange formed on one end and a iirst head welded to the body at the other end; the other unit comprising a second head having a peripheral flange and having a generally central opening therein, and a generally central flue tube welded at one end to the second head and opening outwardly through the opening therein and being formed with a radially inwardly projecting annular flange at its other end; bolts projecting through aligned perforations in the tubular flange and first head and through aligned perforations in the body flange and second head flange, and the tube opening outwardly through the opening in the first head.

5. A range boiler comprising a sheet metal tubular body; two sheet metal heads secured thereto at opposite ends thereof, the heads having each a generally central opening therein; an internal flue tube substantially co-axial of the body, welded at one end to one of the heads and opening outwardly through the opening in that head, and at its other end having a radially inwardly projecting annular flange sealedly secured with respect to the inner surface of the other head and opening outwardly through the opening in the said other head.

6. In an enameled range boiler, a vertically disposable body unit and a head unit; the body unit comprising a tubular sheet metal body and an upper sheet metal head, the upper head being formed from metal thicker than that of the body and having a skirt portion the thickness of which is reduced to substantially that of the body and the skirt being flash welded to the upper end of the body and the upper head having a generally central opening therein, and the body at its lower end being open and having a laterally extending peripheral flange thereon; the head unit comprising a sheet metal lower head having a laterally extending peripheral flange thereon and at its generally central portion being formed with an opening continuing into an upwardly extending skirt, the terminal portion of the skirt being reduced to a thickness less than that of the main portion of the lower head; and a sheet metal flue tube of substantially the same diameter and thickness as the reduced portion of the skirt and being flash welded thereto at its lower end; the upper end of the flue tube having an inwardly radially extending flange formed thereon; the exterior and interior surfaces of the units including their flanges being coated with vitreous enamel; the flanges being bolted together with packing between; and the flue tube flange being bolted to the underside of the upper head with packing therebetween and in alignment with the upper head opening by bolts accessible through the upper head opening.

HARRY R. CANFIELD. 

